Geochemical and isotopic variations in shallow groundwater in areas of the Fayetteville Shale development, north-central Arkansas
Nathaniel R. Warner, Timothy M. Kresse, Phillip D. Hays, Adrian Down, Jonathan D. Karr, R.B. Jackson, Avner Vengosh
2013, Applied Geochemistry (35) 207-220
Exploration of unconventional natural gas reservoirs such as impermeable shale basins through the use of horizontal drilling and hydraulic fracturing has changed the energy landscape in the USA providing a vast new energy source. The accelerated production of natural gas has triggered a debate concerning the safety and possible environmental...
Climate downscaling effects on predictive ecological models: a case study for threatened and endangered vertebrates in the southeastern United States
David N. Bucklin, James I. Watling, Carolina Speroterra, Laura A. Brandt, Frank J. Mazzotti, Stephanie S. Romañach
2013, Regional Environmental Change (13) 57-68
High-resolution (downscaled) projections of future climate conditions are critical inputs to a wide variety of ecological and socioeconomic models and are created using numerous different approaches. Here, we conduct a sensitivity analysis of spatial predictions from climate envelope models for threatened and endangered vertebrates in the southeastern United States to...
Magma mixing and the generation of isotopically juvenile silicic magma at Yellowstone caldera inferred from coupling 238U–230Th ages with trace elements and Hf and O isotopes in zircon and Pb isotopes in sanidine
Mark E. Stelten, Kari M. Cooper, Jorge A. Vazquez, Mary R. Reid, Gry H. Barfod, Josh Wimpenny, Qing-Zhu Yin
2013, Contributions to Mineralogy and Petrology (166) 587-613
The nature of compositional heterogeneity within large silicic magma bodies has important implications for how silicic reservoirs are assembled and evolve through time. We examine compositional heterogeneity in the youngest (~170 to 70 ka) post-caldera volcanism at Yellowstone caldera, the Central Plateau Member (CPM) rhyolites, as a case study. We...
Modeling spatially explicit fire impact on gross primary production in interior Alaska using satellite images coupled with eddy covariance
Shengli Huang, Heping Liu, Devendra Dahal, Suming Jin, Lisa R. Welp, Jinxun Liu, Shuguang Liu
2013, Remote Sensing of Environment (135) 178-188
In interior Alaska, wildfires change gross primary production (GPP) after the initial disturbance. The impact of fires on GPP is spatially heterogeneous, which is difficult to evaluate by limited point-based comparisons or is insufficient to assess by satellite vegetation index. The direct prefire and postfire comparison is widely used, but...
Estimating age ratios and size of Pacific walrus herds on coastal haulouts using video imaging
Daniel H. Monson, Mark S. Udevitz, Chadwick V. Jay
2013, PLoS ONE (8)
During Arctic summers, sea ice provides resting habitat for Pacific walruses as it drifts over foraging areas in the eastern Chukchi Sea. Climate-driven reductions in sea ice have recently created ice-free conditions in the Chukchi Sea by late summer causing walruses to rest at coastal haulouts along the Chukotka and...
Species- and community-level responses combine to drive phenology of lake phytoplankton
Annika Walters, Maria de los Angeles Gonzalez Sagrario, Daniel E. Schindler
2013, Ecology (94) 2188-2194
Global change is leading to shifts in the seasonal timing of growth and maturation for primary producers. Remote sensing is increasingly used to measure the timing of primary production in both aquatic and terrestrial ecosystems, but there is often a poor correlation between these results and direct observations of life-history...
Mapping wildfire burn severity in the Arctic Tundra from downsampled MODIS data
Crystal A. Kolden, John Rogan
2013, Arctic, Antarctic, and Alpine Research (45) 64-76
Wildfires are historically infrequent in the arctic tundra, but are projected to increase with climate warming. Fire effects on tundra ecosystems are poorly understood and difficult to quantify in a remote region where a short growing season severely limits ground data collection. Remote sensing has been widely utilized to characterize...
Sr/Ca proxy sea-surface temperature reconstructions from modern and holocene Montastraea faveolata specimens from the Dry Tortugas National Park
Jennifer A. Flannery, Richard Z. Poore
2013, Journal of Coastal Research (63) 20-31
Sr/Ca ratios from skeletal samples from two Montastraea faveolata corals (one modern, one Holocene, ~6 Ka) from the Dry Tortugas National Park were measured as a proxy for sea-surface temperature (SST). We sampled coral specimens with a computer-driven triaxial micromilling machine, which yielded an average of 15 homogenous samples per...
K-Ar dating and delta O-18-delta D characterization of nanometric illite from Ordovician K-bentonites of the Appalachians: illitization and the Acadian-Alleghenian tectonic activity
Norbert Clauer, Anthony E. Fallick, Dennis D. Eberl, Miroslav Honty, Warren D. Huff, Amelie Auberti
2013, American Mineralogist (98) 2144-2154
Nanometric (<0.02, 0.02–0.05, 0.05–0.1, 0.1–0.2 μm) illite fractions were separated from K-bentonite samples from northwestern Georgia, and studied by X-ray diffraction, oxygen and hydrogen isotope geochemistry, and K-Ar dated to more tightly constrain the tectono-thermal history of the Appalachian orogeny. Their XRD patterns are very similar for a given sample...
Abundance, distribution, and population trends of the iconic Hawaiian Honeycreeper, the ʻIʻiwi (Vestiaria coccinea) throughout the Hawaiian Islands
Eben H. Paxton, P. Marcos Gorresen, Richard J. Camp
2013, Open-File Report 2013-1150
Naturalists in the 1800s described the ʻIʻiwi (Vestiaria coccinea) as one of the most abundant forest birds, detected in forested areas from sea level to tree line across all the major Hawaiian Islands. However, in the late 1800s, ʻIʻiwi began to disappear from low elevation forests, and by the mid-1900s,...
The participatory vulnerability scoping diagram - deliberative risk ranking for community water systems
Peter D. Howe, Brent Yarnal, Alex Coletti, Nathan J. Wood
2013, Annals of the Association of American Geographers (2) 343-352
Natural hazards and climate change present growing challenges to community water system (CWS) managers, who are increasingly turning to vulnerability assessments to identify, prioritize, and adapt to risks. Effectively assessing CWS vulnerability requires information and participation from various sources, one of which is stakeholders. In this article, we present a...
Monitoring sea lamprey pheromones and their degradation using rapid stream-side extraction coupled with UPLC-MS/MS
Huiyong Wang, Nicholas Johnson, Jeffrey Bernardy, Terry Hubert, Weiming Li
2013, Journal of Separation Science (36) 1612-1620
Pheromones guide adult sea lamprey (Petromyzon marinus) to suitable spawning streams and mates, and therefore, when quantified, can be used to assess population size and guide management. Here, we present an efficient sample preparation method where 100 mL of river water was spiked with deuterated pheromone as an internal standard...
Derivation of soil screening thresholds to protect chisel-toothed kangaroo rat from uranium mine waste in northern Arizona
Jo Ellen Hinck, Greg L. Linder, James K. Otton, Susan E. Finger, Edward E. Little, Donald E. Tillitt
2013, Archives of Environmental Contamination and Toxicology (65) 332-344
Chemical data from soil and weathered waste material samples collected from five uranium mines north of the Grand Canyon (three reclaimed, one mined but not reclaimed, and one never mined) were used in a screening-level risk analysis for the Arizona chisel-toothed kangaroo rat (Dipodomys microps leucotis); risks from radiation exposure...
Evidence for deposition of 10 million tonnes of impact spherules across four continents 12,800 y ago
James H. Wittke, James C. Weaver, Ted E. Bunch, James P. Kennett, Douglas J. Kennett, Andrew Moore, Gordon C. Hillman, Kenneth B. Tankersly, Albert C. Goodyear, Christopher R. Moore, I. Randolph Daniel Jr., Jack H. Ray, Neal H. Lopinot, David Ferraro, Isabel Israde-Alcantara, James L. Bischoff, Paul S. DeCarli, Robert E. Hermes, Johan B. Kloosterman, Zsolt Revay, George A. Howard, David R. Kimbel, Gunther Kletetschka, Ladislav Nabelek, Carl P. Lipo, Sachiko Sakai, Allen West, Richard B. Firestone
2013, Proceedings of the National Academy of Sciences of the United States of America (110) E2088-E2097
Airbursts/impacts by a fragmented comet or asteroid have been proposed at the Younger Dryas onset (12.80 ± 0.15 ka) based on identification of an assemblage of impact-related proxies, including microspherules, nanodiamonds, and iridium. Distributed across four continents at the Younger Dryas boundary (YDB), spherule peaks have been independently confirmed in...
Climatic correlates of tree mortality in water- and energy-limited forests
Adrian J. Das, Nathan L. Stephenson, Alan Flint, Tapash Das, Phillip J. van Mantgem
2013, PLoS ONE (8)
Recent increases in tree mortality rates across the western USA are correlated with increasing temperatures, but mechanisms remain unresolved. Specifically, increasing mortality could predominantly be a consequence of temperature-induced increases in either (1) drought stress, or (2) the effectiveness of tree-killing insects and pathogens. Using long-term data from California’s Sierra...
An anti-steroidogenic inhibitory primer pheromone in male sea lamprey (Petromyzon marinus)
Yu-Wen Chung-Davidson, Huiyong Wang, Mara B. Bryan, Hong Wu, Nicholas S. Johnson, Weiming Li
2013, General and Comparative Endocrinology (189) 24-31
Reproductive functions can be modulated by both stimulatory and inhibitory primer pheromones released by conspecifics. Many stimulatory primer pheromones have been documented, but relatively few inhibitory primer pheromones have been reported in vertebrates. The sea lamprey male sex pheromone system presents an advantageous model to explore the stimulatory and inhibitory...
Environmental, depositional and cultural changes in the upper Pleistocene and early Holocene; the Cinglera del Capello Sequence (Capellades, Spain)
Manuel Vaquero, Ethel Allue, James L. Bischoff, Francesc Burjachs, Josep Vallverdu
2013, Quaternaire (24) 49-64
The correlation between environmental and cultural changes is one of the primary archeological and paleoanthropological research topics. Analysis of ice and marine cores has yielded a high-resolution record of millennial-scale changes during the Late Pleistocene and Holocene eras. However, cultural changes are documented in low-resolution continental deposits; thus, their correlation...
Appraising options to reduce shallow groundwater tables and enhance flow conditions over regional scales in an irrigated alluvial aquifer system
Eric D. Morway, Timothy K. Gates, Richard G. Niswonger
2013, Journal of Hydrology (495) 216-237
Some of the world’s key agricultural production systems face big challenges to both water quantity and quality due to shallow groundwater that results from long-term intensive irrigation, namely waterlogging and salinity, water losses, and environmental problems. This paper focuses on water quantity issues, presenting finite-difference groundwater models developed to describe...
Monitoring intensity and patterns of off-highway vehicle (OHV) use in remote areas of the western USA
Douglas S. Ouren, Alisa W. Coffin
2013, Oecologia Australis (17) 96-110
The continued growth of off-highway vehicle (OHV) activities – demonstrated by the dramatic increase in OHV sales, number of users, and areas experiencing OHV use – has elevated concerns about their ecological effects, the impacts on wildlife, and the sustainability of OHV use on secondary and tertiary road networks. Conflicts...
Dynamics of mangrove-marsh ecotones in subtropical coastal wetlands: fire, sea-level rise, and water levels
Thomas J. Smith III, Ann M. Foster, Ginger Tiling-Range, John W. Jones
2013, Fire Ecology (9) 66-77
Ecotones are areas of sharp environmental gradients between two or more homogeneous vegetation types. They are a dynamic aspect of all landscapes and are also responsive to climate change. Shifts in the position of an ecotone across a landscape can be an indication of a changing environment. In the coastal...
Molecular detection and genotyping of Japanese Encephalitis Virus in mosquitoes during a 2010 outbreak in the Republic of Korea
Hyun-Ji Seo, Heung Chul Kim, Terry A. Klein, Andrew M. Ramey, Ji-Hyee Lee, Soon-Goo Kyung, Jee-Yong Park, In-Soo Cho, Jung-Yong Yeh
2013, PLoS ONE (8)
Japanese encephalitis virus (JEV), a mosquito-borne zoonotic pathogen, is one of the major causes of viral encephalitis. To reduce the impact of Japanese encephalitis among children in the Republic of Korea (ROK), the government established a mandatory vaccination program in 1967. Through the efforts of this program only 0-7 (mean...
Potentially induced earthquakes in Oklahoma, USA: links between wastewater injection and the 2011 Mw 5.7 earthquake sequence
Katie M. Keranen, Heather M. Savage, Geoffrey A. Abers, Elizabeth S. Cochran
2013, Geology (41) 699-702
Significant earthquakes are increasingly occurring within the continental interior of the United States, including five of moment magnitude (Mw) ≥ 5.0 in 2011 alone. Concurrently, the volume of fluid injected into the subsurface related to the production of unconventional resources continues to rise. Here we identify the largest earthquake potentially...
Active adaptive management for reintroduction of an animal population
Michael C. Runge
2013, Journal of Wildlife Management (77) 1135-1144
Captive animals are frequently reintroduced to the wild in the face of uncertainty, but that uncertainty can often be reduced over the course of the reintroduction effort, providing the opportunity for adaptive management. One common uncertainty in reintroductions is the short-term survival rate of released adults (a release cost), an...
Petroleum system analysis of the Hunton Group in West Edmond field, Oklahoma
Stephanie B. Gaswirth, Debra K. Higley
2013, American Association of Petroleum Geologists Bulletin (97) 1163-1179
West Edmond field, located in central Oklahoma, is one of the largest oil accumulations in the Silurian–Devonian Hunton Group in this part of the Anadarko Basin. Production from all stratigraphic units in the field exceeds 170 million barrels of oil (MMBO) and 400 billion cubic feet of gas (BCFG),...
Revision of Fontes & Garnier's model for the initial 14C content of dissolved inorganic carbon used in groundwater dating
Liang-Feng Han, Niel Plummer
2013, Chemical Geology (351) 105-114
The widely applied model for groundwater dating using 14C proposed by Fontes and Garnier (F&G) (Fontes and Garnier, 1979) estimates the initial 14C content in waters from carbonate-rock aquifers affected by isotopic exchange. Usually, the model of F&G is applied in one of two ways: (1) using a single 13C...
